1. Field of the Invention
The present invention relates to a camera that can perform data communication with external devices, and, in particular, to such cameras that use a dummy film cartridge to perform data communication with the external devices.
2. Description of Related Art
U.S. Pat. No. 5,032,854 discloses a camera in which a bar code pattern is provided on the top surface of a film cartridge for relating information about the film, including the number of exposures and the film sensitivity, to the camera. The bar code pattern is read by a photo-reflector provided within the camera. In addition, a camera is known in which a DX code indicating the film sensitivity and related information, which is provided on the side surface of the film, is read by a device disposed within the camera.
Because variations exist in the properties of photometry elements used in cameras for automatic exposure the need arises for the input of adjustment values into each camera in order to ensure proper camera performance. In addition, during shipping tests of cameras, lens driving tests and shutter opening and closing tests must be conducted by controlling the camera using an external device, such as a personal computer. Furthermore, the camera may need to transmit data to the external device in order to record photographic conditions such as the exposure value or similar parameters.
In these cases, it has been proposed to provide a terminal on the camera for data communication purposes that can be connected to an external device. Providing such a terminal, however, raises costs and increases the size of the camera.
Alternatively, it has been proposed to perform data communication with the camera by providing a dummy cartridge having the same shape as the film cartridge and that fits in the cartridge chamber. A DX code terminal is provided on the dummy cartridge for data communication with the camera. This method offers the advantage that a previously existing connection terminal provided in the camera for use with DX code input can also be used for data communication purposes. However repeatedly inserting and removing the dummy cartridge causes friction on the connection components that can result in poor electrical contact.